Joystick device

ABSTRACT

A joystick device includes a case so that first and second rocking members are respectively supported in a overlapped manner by first and second bearings formed in the case with their first and second elongate holes positioned perpendicular to each other. The operation of the lever inserted through the first and second elongate holes causes tilt movement in at least one of the rocking members so that the movement of the rocking member is supplied as a pulse signal by a detecting device. The lever includes an engaging portion engaged with the rocking member on the upper side, and a spherical portion formed at a position above the same rocking member. The cover has a hole having an inner peripheral edge with which an outer peripheral surface of the spherical portion is contacted so that the lever is operable in every direction. A spring is provided with the case, which acts to press down the rocking member thereby returning the lever to a neutral position.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to joystick devices. More particularly, this invention is concerned with a joystick device having an operating axis (lever) arranged for tilt movement in a desired direction so as to output an electric signal depending upon a state of inclination in the lever (the direction and the angle of inclination).

2. Prior Art

One example of a joystick device is described for example in Japanese Provisional Utility Model Publication No. H2-68404. This conventional art joystick device has a pair of rocking members, each having an elongate hole arranged such that these elongate holes are placed perpendicular to each other. A lever is inserted through the respective elongate holes of the pair of the rocking members so that the lever is allowed to tilt in every direction about a predetermined point as a fulcrum point. The lever is projected to extend from a predetermined location of a cover attached to a case in which the rocking members are accommodated.

In the above conventional art, the lever has a lower portion inserted through an elongate hole of one rocking member to be attached to the same rocking member through a shaft extending perpendicular to a lengthwise direction of the elongate hole, thereby preventing the lever from being removed and from rotating about its own axis. Consequently, the fulcrum point of the lever is located on the shaft where the lower portion of the lever is attached to the rocking member. To this end, it is necessary to provide a relatively large opening in the cover in order to obtain a sufficient range of tilt movement of the lever.

However, if a large opening is formed in a cover, dust or dirt is often allowed to intrude into an interior of the case through the opening, impairing operational reliability in rotational or sliding portions of the joystick device.

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide a joystick device which is capable of positively preventing the lever from being removed and from rotating about its own axis, and positively preventing against intrusion of dust and dirt into the interior of the case.

It is another object of the present invention to provide a joystick device in which the lever can automatically and reliably be returned to a neutral position.

It is another object of the present invention to provide a joystick device in which an electric signal is provided with accuracy in response to the position and the angle of tilt of the lever.

The present invention relates to a joystick device comprising: a case; first and second bearing portions formed in the case to have respective axes extending perpendicular to each other; a first rocking member having first support shafts supported by the first bearings and a first elongate hole that is long in an axial direction of the first support shaft; a second rocking member having second support shafts supported by the second bearing portions, and a second elongate hole that is long in an axial direction of the second support shaft, the first rocking member and the second rocking member being arranged in such an overlapped state that the first elongate hole and the second elongate hole extend perpendicular to each other; a lever inserted through the first elongate hole and the second elongate hole, the lever when operated causing rocking movement in at least one of the first rocking member and the second rocking member, the lever including an engaging portion in engagement with one of the first rocking member and the second rocking member and a spherical portion formed at a position thereof above the second rocking member; a detecting means for detecting rocking movement in at least one of the first rocking member and the second rocking member to output an electric signal; a cover attached to the case and having a hole defined by an inner peripheral edge that contacts with an outer peripheral surface of the spherical portion, the hole holding the spherical portion so that the lever can be operated in every direction; and a spring provided within the case so as to return the lever to a neutral position.

That is, in accordance with one aspect of the present invention the lever inserted through the elongate holes of the pair of rocking members has the projection that is latched to either one of the rocking members so as to prevent the lever from being removed. The lever projects through the hole provided in the cover. The lever is provided with the spherical portion supported in contact with the edge of the hole for tilt movement about the contact point as a fulcrum point in every direction.

Therefore, according to the present invention, it is not necessary to provide a large-sized opening to obtain a range of tilt movement of the lever. Furthermore, since the spherical portion of the lever is in contact with the edge of the hole on the cover side, the location at which the lever projects out of the cover is closed. This eliminates the possibility that dust or dirt will intrude into the case to possibly impair the operational reliability of rotational or sliding portions of the lever.

Also, the lever at the spherical portion thereof is supported by the contact point as a fulcrum point for tilt movement thereabout in every direction. A rotation-preventive means is provided at the contact point between the spherical portion and the inner peripheral edge of the hole, to prevent the lever from rotating about an axis thereof. Moreover, the projection of the lever is structurally latched to the rocking member, preventing removal and rotation of the lever about its own axis.

In one aspect of the present invention, a rotation-preventive mechanism is provided, for preventing the lever from rotating about its own axis, at a position of contact between the spherical portion and the edge of the hole in the cover. In this aspect, the projection of the lever is latched to pair of the rocking members supported through support shafts by the bearing portions, thereby preventing the lever from being removed. Also, the rotation-preventive mechanism prevents the lever from being rotated about its own axis. This rotation-preventive mechanism is provided at the contact point between the spherical portion of the lever and the hole edge on the case side, so that it is not necessary to provide, at a location of the case where the lever extends, such an opening that induces intrusion of dust or dirt therethrough.

The rotation-preventive means may adopt a detailed structure that includes a groove formed in the spherical portion to extend in a parallel direction of the lever, and a hub formed to project from the inner peripheral edge of the hole to be slidably fitted in the groove in a manner contacting groove walls and a groove bottom thereof. If such a structure is employed for the rotation-preventive mechanism, the portion at which the lever extends from the cover is completely closed such that the surface of the spherical portion of the lever contacts the edge of the hole on the cover side and the groove walls and the groove bottom of the groove contacts the hub on the cover side, thereby eliminating a gap of which would permit intrusion of dust and dirt.

Also, it is possible to adopt such a structure that the case is separated as an inner case provided with two sets of bearings and an outer case for accommodating this inner case so that a cover is mounted on the outer case. In such an arrangement, the inner case and the rocking members can be accommodated within a space enclosed by the outer case and the cover, eliminating intrusion of dust or dirt.

Furthermore, it is possible to adopt a structure having a circular hole provided at a central portion of the cover so that the wall surrounding the hole has a gradient descending toward the hole, flat surfaces formed at respective end portions of the one pair of rocking members such that they are in the same horizontal plane when the lever is in a neutral state, and the spring is accommodated within a space defined around the taper wall so as to be interposed between the cover and the respective flat surfaces. In such an arrangement, a press-down member is preferably disposed between a lower end of the spring and the respective flat surfaces of the one pair of rocking members to have a surface thereof placed in a horizontal plane when the lever is in the neutral state, so that the surface of the press-down member and the respective flat surfaces of the one pair of rocking members overlap by surface contact with each other.

In this aspect, since the space around the cover taper wall is effectively utilized as a space for accommodating the spring, it is not necessary to separately provide a spring accommodation space between the cover and the case, correspondingly promoting miniaturization. The force of the spring is evenly applied through the press-down member to the respective flat surfaces of the one pair of rocking members, thereby improving the reliability of the lever to return to the neutral position.

In the present invention, the displacement of a displacing member is detected by a 2-phase 2-channel detecting element so that it is possible to obtain an electric signal with accuracy in dependence upon a tilt state of the lever.

The above described objects and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an analog joystick as one embodiment of the present invention;

FIG. 2 is a perspective view showing, by partly omitting, an interior structure of the FIG. 1 embodiment;

FIG. 3 is an exploded perspective view showing an inner case, rocking members and a lever of the FIG. 1 embodiment;

FIG. 4 is an exploded perspective view showing an outer case, a circuit board, etc., of the FIG. 1 embodiment;

FIG. 5 is an exploded perspective view showing a grooved ring, a spring, a cover, etc. of the FIG. 1 embodiment;

FIG. 6 is a plan view showing, by omitting the cover and the lever, the FIG. 1 embodiment;

FIG. 7 is a sectional view taken on line VII--VII in FIG. 1;

FIG. 8 is a sectional view taken on line VIII--VIII in FIG. 1;

FIG. 9 is a segmentary sectional view taken on line IX--IX in FIG. 1;

FIG. 10 is a circuit diagram showing a pulse generating circuit of the FIG. 1 embodiment;

FIG. 11 is an illustrative view showing the relationship between slits and light receiving elements of the FIG. 1 embodiment;

FIG. 12 illustrates waveform diagrams of pulse signals generated by the FIG. 10 circuit;

FIG. 13 is an exploded perspective view showing another embodiment of the present invention;

FIG. 14 is an illustrative view showing an essential part in a neutral state of the lever in the FIG. 13 embodiment;

FIG. 15 is an illustrative view showing the essential part of the FIG. 13 embodiment when the lever is in tilting, FIG. 16 is a sectional view showing another embodiment having a projection in the lever that is latched to the lower rocking member to prevent removal; and

FIG. 17 is a sectional view showing an embodiment having a case formed by a singular member.

EMBODIMENTS

Referring to FIG. 1, an analog joystick 10 as one embodiment of the present invention includes a joystick unit 12. The joystick unit 12 includes a housing 20 formed by an outer case 14 and a cover 18, so that an inner case 22 (FIG. 2) is accommodated within the outer case 14 or the housing 20.

As shown in FIG. 2 and FIG. 3, the inner case 22 has a recessed portion 24 formed in a bowl form at a central portion thereof. In a manner of surrounding the recessed portion 24, two pairs of support plates 26a and 26b, and 28a and 28b are provided spaced at an angular interval of 90 degrees from one another so that semicircular bearings 30a and 30b, and 32a and 32b are respectively provided in these support plates 26a and 26b, and 28a and 28b. The bearings 30a and 30b or 32a and 32b are disposed on a same axial line so that the bearings 30a and 30b, and 32a and 32b have their respective axes that intersect perpendicular to each other at a same height level. The inner case 22 has blades or disks 34 and 36 rotatably supported on respective side surfaces thereof in a manner such that their rotational axes are perpendicular to each other. Similarly, the disk 36 is provided with a gear (not shown).

The joystick unit 12 further includes rocking members 40 and 42. One rocking member 40 is formed by an arcuate member having an elongate hole 44 formed in a lengthwise direction to have support shafts 46a and 46b at respective ends. From these support shafts 46a and 46b are extended shaft end portions 50a and 50b respectively having flat surfaces 48a and 48b. The shaft end portion 50b on one side is provided with a fan-shape gear 52. The other rocking member 42 is different from the one rocking member 40 in that it is formed by an arcuate member having a smaller radius of curvature than that of the one rocking member 40, but is similar in structure in other respects. That is, reference numeral 54 designates an elongate hole, reference numerals 56a and 56b are support shafts, reference numeral 58a and 58b are flat surfaces, reference numerals 60a and 60b are shaft end portions, and reference numeral 62 is a gear.

The pair of rocking members 40 and 42 are received at their support shaft 46a and 46b, and 56a and 56b by respective two sets of bearings 30a and 30b, and 32a and 32b, to be supported for rocking movement. These rocking members are arranged to overlap by being spaced at a given interval with their elongate holes positioned perpendicular in lengthwise direction relative to each other. In this manner, the fan-shape gear 52 of the one rocking member 40 attached to the inner case 22 meshes with the above-stated gear 38. Similarly, the fan-shape gear 62 of the other rocking member 42 meshes with the gear 39 (FIG. 6 and FIG. 8). The above-mentioned flat surfaces 48a and 48b and 58a and 58b are in the same horizontal plane when the lever 64 is in a neutral state, as stated later.

As shown in FIG. 3, the lever 64 has a projection 66 formed radially outwardly projecting at one end portion thereof, a spherical portion 68 formed at an intermediate portion, and an connecting portion 70 formed at the other end portion. The spherical portion 68 has grooves 72 formed to extend in a parallel direction at locations spaced by 180 degrees. The lever 64 is provided with a diameter not greater than the shorter diameter of the elongate holes 44 and 54 of the rocking members 40 and 42, preferably to such a dimension that the lever is slidably received through the elongate holes 44 and 54 without chattering. The lever 64 at the one end is inserted through the elongate hole 44 and 54 with the projection 66 thereof engaged with the elongate hole 44 of the lower rocking member 40. Consequently, the projection 66 of the lever 64 projects in a direction perpendicular to the lengthwise direction of the elongate hole 54 of the upper rocking member 42 attached to the inner case 22. This prevents the lever 64 from being removed by the abutment of the projection 66 against the upper rocking member 42 when the lever 64 is pulled in an upward direction.

The mechanism assembly constructed as shown in FIG. 2 is placed within the outer case 14 shown in FIG. 1. In this case, the inner case 22 is fixed to the outer case 14 by using an appropriate means such as screws, not shown.

The inner case 22 has, as will be clearly understood from FIG. 3, photointerrupters 74 and 76 provided in a manner opposite to the respective two blades or disks 34 and 36. The photointerrupters 74 and 76 each include light emitting elements and light receiving elements (not shown) so that the light emitted from the light emitting element passes through the slits 34a and 36a formed in the blade or disk 34 and 36 to be received by the light receiving element. Consequently, the photointerrupters 74 and 76 detect the slits 34a and 36a to output a pulse signal in response to the slits 34a and 36a by the rotation of the blade or disk 34 and 36.

Incidentally, the height level of the axis (the support shafts 46 and 56) of tilt movement of the rocking members 40 and 42 is in coincident with the height level of the center of the spherical portion 68 of the lever 64.

The outer case 14 incorporates therein a circuit board 80 connected with a flexible circuit 78 as shown in FIG. 4, wherein this circuit board 80 has an interconnection pattern to which the light emitting elements and the light receiving elements included in the photointerrupters 74 and 76 are electrically connected.

As will be understood from FIG. 5, FIG. 7 and FIG. 8, a grooved ring 82 rests on the flat surfaces 48 and 58 formed in the pair of rocking members 40 and 42, and a coil spring 84 is disposed on the grooved ring 82. The grooved ring 82 is an example of a press-down member, which becomes horizontal at its underside surface when lever 64 is in a neutral state so that the underside surface of the ring 82 overlies the flat surfaces 48 and 58 in surface contact therewith.

As shown in FIG. 1 and FIG. 5, the cover 18 has a guide ring 86 mounted thereon, which ring 86 is formed at a central portion with a circular hole 88. The guide ring 86 further includes a guide wall 90 that rises in gradient from an periphery of the hole 88 toward the outward. That is, the guide wall 90 is formed as a whole in a "cone" form. The guide wall 90 has an outer edge in a circular form as shown in FIG. 5 or an octagonal form as shown in FIG. 1, as viewed from above.

Here, as shown in FIG. 7 and FIG. 8, the spring 84 is accommodated around the guide wall 90 within a space 92 so that it is interposed between the cover 18 and the flat surfaces 48 and 58 through the grooved ring 82. As a result, the space 92 around the guide wall 90 in the cover 18 is effectively utilized as an accommodation space for the spring 84 without wasted space.

Incidentally, the diameter of the hole 88 of the guide ring 86 is approximately the same dimension as the diameter of the outer periphery of the spherical portion 68. Consequently, the hole 88 is in contact at its edge with the spherical portion 68 of the lever 64 so that the lever 64 is supported by the spherical portion 68 and the hole 88 for tilt movement in every direction, as shown in FIG. 8. As shown in FIG. 7, the hole 88 of the guide ring 86 has circular hubs 94 which project radially inward at two locations spaced by 180 degrees so that these hubs 94 are respectively fitted in the parallel grooves 72 of in the spherical portion 68. These hubs 94 have an axis thereof coincident with the axis of tilt movement in the rocking members 40 and 42. As will be understood from FIG. 9, the hub 94 has an tip end 96 in slidable contact with an accurate groove bottom 98 in the groove 72 with outer peripheral surfaces 100 thereof slidably contacting groove walls 102 in the groove 72.

If the parallel groove 74 in the spherical portion 68 is received by the hub 94 formed in the cover 18 in a state as above, the lever 64 is allowed to move about the axis of the hubs 94, but cannot be rotated about an axis of the lever 64 itself. Therefore, the grooves 72 of the spherical portion 68 and the hubs 94 constitute a rotation-preventive mechanism that serves to prevent the lever 64 from rotating about its own axis.

Also, when the cover 18 is fitted over the outer case 14, the spring 84 is compressed between the grooved ring 82 and the cover 18. As a result, the flat surfaces 48 and 58 of the pair of the rocking members 40 and 42 are depressed at all times by the force of the spring 84 via the grooved ring 82. This depressing action elastically urges at all times the pair of rocking members 40 and 42 in a manner not to incline in any direction. As a result, the lever 64 is held in an uprightly standing position or a neutral state at all times by the elastically urging force.

A manipulation knob 104 is attached onto the lever 64 through a connecting portion 70 thereof, as shown in FIG. 1 and FIG. 5. The manipulation knob 104 has a top surface formed with a recessed portion 106 for resting fingers thereon.

As stated above, the spherical portion 68 of the lever 64 is in contact with the edge of the hole 88 on the cover 18 side, and the grooves 72 in the spherical portion 68 are respectively received by the hubs 94 of the cover 18 so that the hub 94 is always in contact with the groove bottom 98 and the groove walls 102. Therefore, no gap exists between the lever 64 projecting from the hole 88 and the cover 18. Consequently, no dust or dirt intrudes into the interior of the housing 20 (FIG. 1) maintaining the initial reliability of rotational and sliding portions of the joystick unit 12 over a long time period.

In the analog joystick 10 constructed as above, the rocking member 40 and/or 42 is rocked in dependence upon the direction and the angle of tilt of the lever 64. If the blade or disk 34 and/or 36 is rotated depending upon the angle of movement in the rocking member 40 and/or 42, pulses are outputted by the photointerrupters 74 and 76 in accordance with the amount of rotation of the disk 34 and/or 36. The pulses are utilized as a coordinate signal for a direction of an X-axis and/or a Y-axis.

Here, explanation will be made on the generation of pulses by the disks 34 and 36 and the photointerrupters 74 and 76, with reference to FIG. 10 to FIG. 12. Note that the below explanation will be principally on interaction between the one disk 34 and the photointerrupter 74. The interaction between the other disk 36 and the photointerrupter 76 is similar to this, the explanation thereof being omitted.

As stated above, the slits 34a are formed at a predetermined pitch in an outer periphery of the disk 34 so that the slit 34a is detected by the photointerrupter 74. The photointerrupter 74 includes, as shown in FIG. 10, one light emitting element 741 and four light receiving elements 74a, 74b, 74c and 74d for receiving the light from the light emitting element 741. The disk 34, i.e., the slits 34a, is interposed between the light emitting element 741 and the light receiving elements 74a, 74b, 74c and 74d. The light receiving elements 74a-74d are of a 2-channel 2-phase photodiode. The respective outputs of the first light receiving element 74a and the third light receiving element 74c are inputted through an amplifier to an operational amplifier 108 as shown in FIG. 10, while the respective outputs of the second light receiving element 74b and the fourth light receiving element 74d are inputted through an amplifier to an operational amplifier 110. That is, the light receiving elements 74a-74d each have an electric current in an amount commensurate with the intensity of the light from the light emitting element 741. This electric current is converted by a resistance connected to an output of the amplifier so that the terminal voltage of the resistance is inputted as an output voltage of the light receiving element 74a-74d to the amplifier 108 or 110. The operational amplifiers 108 and 110 each output electric voltage in an magnitude commensurate with the difference in two input voltages so that the output voltages are respectively converted by waveform shaping circuits formed by transistors 112 and 114 into pulse signals P1 and P2.

As shown in FIG. 11, the pitch of the light receiving elements 74a-74d and the pitch of the slits 34a in the first disks 34 are set in a relationship as stated below. That is, when two adjacent light receiving elements 74a and 74b come to a slit 34a, the remaining two light receiving elements 74c and 74d are in a shadow 34b between slits 34a. Conversely, when the light receiving elements 74c and 74d go to a slit 34a, the light receiving elements 74a and 74b are in a shadow 34b between slits 34a. That is, the light receiving element 74a and the light receiving element 74c have a phase difference of 180 degrees, while the light receiving element 74b and the light receiving element 74d have a phase difference of 180 degrees. Consequently, as the disk 34 rotates, the area of light reception by the light receiving element 74a and 74c varies as shown in FIG. 12(B).

Therefore, the operational amplifier 108 receives two input voltages Va and Vc different in phase by 180 degrees, as shown in FIG. 12(C), while the operational amplifier 110 receives two input voltages Vb and Vd different in phase by 180 degrees, as shown in FIG. 12(D). The voltage Vc is applied to a (+) input of the operational amplifier 108, and the voltage Va is applied to a (-) input thereof. Therefore, when the voltage Va is in a positive polarity, the difference between the voltage Va and the voltage Vc becomes great, whereas when the voltage Va is in a negative polarity, the difference between the voltage Va and the voltage Vc becomes small. To this end, when the voltage Va is in a negative polarity, the operational amplifier 108 has a decreased output voltage to turn off the transistor 112. When the voltage Va is in a positive polarity, the output voltage of the operational amplifier 108 increases to turn on the transistor 112. Therefore, the transistor 112 outputs at a collector thereof a pulse signal P1 as shown in FIG. 12(E), depending upon the rotation of the disk 34. Similarly, when the voltage Vd is in a negative polarity the output voltage of the operational amplifier 110 decreases to turn off the transistor 114, whereas when the voltage Vd is in a positive polarity the output voltage of the operational amplifier 110 increases to turn on a transistor 114. Therefore, the transistor 114 outputs at a collector a pulse signal P2 as shown in FIG. 12(F), in dependence upon the rotation of the disk 34.

In this manner, there is a difference in phase by 90 degrees between the pulse signal P1 and the pulse signal P2 as shown in FIG. 12(E) and FIG. 12(F). It is therefore, possible to determine a direction of rotation of the disk 34 by judging which one of the pulse signal P1 and the pulse signal P2 is outputted earlier.

In the above analog joystick 10, if the lever 64 held in a neutral state by the force of the spring 84 (FIG. 5, FIG. 7 and FIG. 8) is operated at a manipulation knob by fingers, it is tilted about the axis of the hubs 94 against the force of the spring 84. It is assumed that this direction of tilt movement is a "forward-backward direction". When the lever 64 is being moved about the axis of the hubs 94 to an arbitrary position, the spherical portion 68 can be rotated in the parallel direction along the hubs 94 as a guide that are fitted in the grooves 72. Accordingly, it is possible to move the lever 64 in a "left-right direction" with respect to the above "forward-backward direction". Therefore, the lever 64 is allowed to tilt about the spherical portion 68 as a center in every direction.

If the lever 64 is moved in an arbitrary direction and then the manipulation knob 104 of the lever 64 is released by the fingers, the force of the spring is transmitted to the lever 64 via the pair of rocking members 40 and 42 thereby returning the lever 64 to the neutral state. In this case, the force of the spring 84 is evenly applied to the flat surfaces 48 and 58 (FIG. 7 and FIG. 8) of the pair of the rocking members 40 and 42 through the grooved ring 82, thereby improving reliability in return of the lever 64 to the neutral state.

When the lever 64 is moved in an arbitrary direction, the pair of the rocking members 40 and 42 are respectively moved by an amount commensurate with the amount of rocking movement thereof in the forward-backward direction and the left-right direction. In accordance with the angle of movement in the rocking members 40 and 42, the disks 34 and 36 are rotated so that pulse signals are outputted in response to the rotational amount.

Although in the above embodiment the outer case 14 and the inner case 22 were employed, the inner case 22 may be omitted by providing bearing portions 30 and 32 in the outer case 14, or providing photointerrupters 74 and 76 in the outer case 14.

Also, in the above embodiment, the structure that the pair of rocking members 40 and 42 are depressed at their flat surfaces 48 and 58 by the force of the spring 84 through the grooved ring 82 was employed as a means for elastically urging at all times the lever 64 toward the neutral state. However, other structure may be adopted as a means for elastically urging the lever 64 always toward the neutral state.

Referring to FIG. 13, another embodiment of the present invention is shown, which is similar to the above embodiment except as noted below. In the figure, the same and corresponding parts or elements are denoted by the same reference numerals, thereby omitting explanations thereof.

Of the rocking members 40 and 42, one rocking member 40 has a support shaft 46a on one side extending in an axial direction to have a protuberance 118 provided opposite to the extended shaft portion 116 in a manner integral therewith. The protuberance 118 has an opening 120 formed therethrough. The other rocking member 42 also has a support shaft 56a on one side extending in one axial direction to have a protuberance 124 integrally provided with an extended shaft portion 122 in a manner opposite thereto. The protuberance 124 is provided with an opening 126.

Torsion coil springs 128 and 130 each have a pair of leg portions 128a and 128b, 130a and 130b at respective ends. One torsion coil spring 128 is fitted over the extended shaft portion 116 of the one rocking member 40 so that the leg portions 128a and 128b are passed through the opening 124 of the protuberance 122 to be received in the recess portion 132 of the inner case 22. These leg portions are supported by elastic abutment against the opposite wall surfaces 132a and 132b (see FIG. 14) in the recess portion 132. Similarly, the other torsion coil spring 130 is fitted over the extended shaft portion 122 of the other rocking member 42 so that the legs 130a and 130b are passed through the opening 126 of the protuberance 124 to be received within the recess portion 134 in the inner case 22. These legs are supported by elastic abutment against the opposite wall surfaces (not shown) in the recess portion 134.

In this embodiment, when the lever 64 is not moved in any direction from the neutral state, the pair of leg portions 128a and 128b of the torsion coil spring 128 are passed through the opening 120 with slight gap space left in the opening 120 of the protuberance 118 of the rocking member 40, as shown in FIG. 14. Accordingly, the force of the spring does not act upon the protuberance 118.

When the lever 64 is inclined to thereby move the rocking member 40 by an angle θ as shown in FIG. 15 about the support shaft 116, the protuberance 118 is inclined along with the rocking member 40 as shown in FIG. 15 so that one leg 128b is urged against the force of the torsion coil spring 128 by an edge of the opening 120 of the protuberance 118. Accordingly, when the lever 64 is released by the finger, the force of the torsion coil spring 128 is transmitted to the rocking member 40 via the leg portion 128b. Consequently, as the rocking member 40 is returned, the lever 64 is returned to the neutral state. This is true for the case where the lever 64 is moved in a reverse direction and then released from the fingers. Furthermore, where the lever 64 is moved in such a direction that the other rocking member 42 is moved and then the lever 64 is released from the fingers, the torsion coil spring 130 behaves in the same operational manner as that of the torsion coil spring 128, thereby returning the lever 64 to the neutral state.

In the above embodiment, the projection 66 of the lever 64 is fitted in the elongate hole 44 in the lower rocking member 40 as shown in FIG. 7 and FIG. 8. Consequently, when the lever 64 is pulled upward, the projection 66 is brought into engagement with the upper rocking member 42 thereby preventing the lever 64 from being removed. However, it is also possible to prevent the lever 64 from being removed by latching the projection of the lever 64 to the lower rocking member 40.

FIG. 17 shows an embodiment having a case 16 formed by a single member, wherein one pair of the rocking members at their support shafts are supported for rocking movement within the case 16. Incidentally, there appear in FIG. 17 no portions for supporting the support shafts of the rocking member 40, but in this respect this embodiment is similar to the aforestated embodiment.

In the above embodiment, the disks 34 and 36 were used as displacing members coupled to the rocking members. However, the displacing members may be of a member that is coupled to the rocking member to be linearly displaced by rocking movement of the rocking member.

Also, in the above embodiment, the slits formed in the displacing member were detected by the photointerrupter so as to output electrical signals. However, the detected portions may be formed by magnet pieces placed at a given interval in a displacing direction of the displacing member, instead of the slits. In such a case, magnetically-sensitive effect elements such as Hall elements can be utilized as detecting elements in place of the photointerrupters. In such a case, however, an electric signal commensurate with the tilt state of the lever is available with accuracy by using 2-channel 2-phase detecting elements in a manner similar to the above embodiment.

Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims. 

What is claimed is:
 1. A joystick device comprising:a case; first and second bearing portions formed in said case to have respective axes extending perpendicular to each other; a first rocking member having first support shafts supported by said first bearing portions, and a first elongate hole that extends in an axial direction of said first support shafts; a second rocking member having second support shafts supported by said second bearing portions, and a second elongate hole that extends in an axial direction of said second support shaft, said first rocking member and said second rocking member being arranged in an overlapped state such that said first elongate hole and said second elongate hole extend perpendicular to each other and having a first flat portion and a second flat portion involved in a same plane; a lever inserted through said first elongate hole and said second elongate hole, said lever when operated causing rocking movement in at least one of said first rocking member and said second rocking member, said lever including an engaging portion in engagement with one of said first rocking member and said second rocking member and a spherical portion formed at a position thereof above said second rocking member; a detector operable to detect rocking movement in at least one of said first rocking member and said second rocking member to output an electric signal; a cover attached to said case and having a hole defined by an inner peripheral edge that contacts with an outer peripheral surface of said spherical portion, said hole holding said spherical portion so that said lever can be operated in every direction; and a spring provided within said case so as to return said lever to a neutral position by elastically repelling downward said first flat portion and said second portion in a constant manner.
 2. A joystick device according to claim 1, wherein said case includes an inner case (22) and an outer case (14) accommodating said inner case, said cover being fitted on said outer case.
 3. A joystick device according to claim 1, further comprising a rotation-preventive device provided at a position of contact between said spherical portion and said inner peripheral edge of said hole to prevent said lever from rotating about an axis thereof.
 4. A joystick device according to claim 3, wherein said rotation-preventive device includes a groove formed in said spherical portion to extend in a parallel direction, and a hub which projects from said inner peripheral edge of said hole to be slidably fitted in said groove.
 5. A joystick device according to claim 1, wherein said spring includes a first torsion coil spring (128) that is fitted over said first support shaft and has two first leg portions (128a, 128b) fixed in said case, and a second torsion coil spring (130) that is fitted over said second support shaft and has two second leg portions (130a, 130b) fixed in said case.
 6. A joystick device according to claim 5, wherein said first rocking member includes a first opening (120) formed beneath said first support shaft, said first leg portions of said first torsion coil spring being passed through said first opening to be fixed in said case, said second rocking member including a second opening (126) formed beneath said second support shaft, said second leg portions of said second torsion coil spring being passed through said second opening to be fixed in said case.
 7. A joystick device according to claim 1, wherein said first rocking member and said second rocking member respectively include a first flat portion (48a, 48b) and a second flat portion (58a, 58b) which are involved in a same plane, said spring (84) being interposed between said first flat portion and said second flat portion and said cover to elastically repel downward said first flat portion and said second flat portion in a constant manner.
 8. A joystick device according to claim 7, wherein said cover has a wall that rises from said hole toward an outward portion thereof to thereby form a space around said wall beneath said cover, said spring being accommodated within said space.
 9. A joystick device according to claim 7 or 8, further comprising a press-down member disposed between a lower end of said spring and said first and second flat surfaces to have a horizontal surface when said lever is at the neutral position, the repellent force of said spring being transmitted through said press-down member to said first and second flat planes.
 10. A joystick device according to claim 1, wherein said detector includes a first detecting device including a first displacing member coupled to said first rocking member to be displaced depending upon rocking movement of said first rocking member, a first detectable portion formed in said first displacing member, and a first detecting element for detecting said first detectable portion, and a second detecting device including a second displacing member coupled to said second rocking member to be displaced depending upon rocking movement of said second rocking member, a second detectable portion formed in said second displacing member and a second detecting element for detecting said second detectable portion.
 11. A joystick device according to claim 10, wherein said first detected portion is placed at a predetermined interval in a displacing direction of said first displacing member, said second detected portion being placed at a predetermined interval in a displacing direction of said second displacing member,each of said first detecting element and said second detecting element including at least four detecting portions so that two adjacent detecting portions simultaneously detect said detectable portions while the remaining two detecting portions are between said detectable portions, and said detector further including a first operational amplifier which receives outputs of first and third detecting portions and a second operational amplifier which receives outputs of second and fourth detecting portions to thereby determine the direction of displacement in said first displacing member and said second displacing member.
 12. A joystick device according to claim 11, wherein each of said first detectable portion and said second detectable portion includes a plurality of slits, said detecting portion being a light receiving portion for receiving light passed through said slit.
 13. A joystick device according to claim 11, wherein each of said first detectable portion and said second detectable portion includes a plurality of magnetic portions, said detecting portion being a magnetically-sensitive portion for receiving a magnetic force of said magnetic portion.
 14. A joystick device comprising:an operating member to be tilt-operated by a hand; an initial-position returning mechanism arranged to be automatically returned to an initial position thereof when said operating member is released from an external force; a first interacting member arranged for interacting solely with movement in a first direction of said operating member; a second interacting member arranged for interacting solely with movement in a second direction perpendicular to the first direction of said operating member; a first displacing member having a gear portion in mesh with a gear portion formed in said first interacting member so as to be rotated based on movement of said first interacting member; a second displacing member having a gear portion in mesh with a gear portion formed in said second interacting member so as to be rotated based on movement of said second interacting member; a first sensor including a two channel, two phase detecting element for detecting an amount of displacement in said first displacing member to output a pulse; a second sensor including a two channel, two phase detecting element for detecting an amount of displacement in said second displacing member to output a pulse; a spherical portion formed at a portion of center of tilt movement in said operating member; a cover having a hole defined by an inner peripheral edge in contact with an outer peripheral surface of said spherical portion, said hole supporting said spherical portion so that said lever can be operated in every direction; and a rotation-preventive means provided at a contact position between said spherical portion and said inner peripheral edge of said hole to prevent said lever from rotating about an axis thereof.
 15. A joystick device, comprising:an operating member to be tilt-operated by a hand; an initial-position returning mechanism arranged to be automatically returned to an initial-position thereof when said operating member is released from an external force; a first interacting member arranged for interacting solely with movement in a first direction of said operating member, and having an elongate hole; a second interacting member arranged for interacting solely with movement in a second direction perpendicular to said first direction of said operating member, and having a second elongate hole extending in a direction perpendicular to a direction that said first elongate hole extends, said second interacting member being positioned below said first interacting member; and an engaging projection integrally formed in the vicinity of a lower end of said operating member to project along said second elongate hole to a length greater than a width of said first elongate hole, said engaging projection being slidable inside said second elongate hole and engaged with a bottom surface of said first interacting member to thereby prevent said operating member from being upwardly pulled off.
 16. A joystick device comprising:a case; first and second bearing portions formed in said case to have respective axes extending perpendicular to each other; a first rocking member having first support shafts supported by said first bearing portions, and a first elongate hole that extends in an axial direction of said first support shafts; a second rocking member having second support shafts supported by said second bearing portions, and a second elongate hole that extends in an axial direction of said second support shaft, said first rocking member and said second rocking member being arranged in an overlapped state such that said first elongate hole and said second elongate hole extend perpendicular to each other and having a first flat portion and a second flat portion involved in a same plane; a lever inserted through said first elongate hole and said second elongate hole, said lever when operated causing rocking movement in at least one of said first rocking member and said second rocking member, said lever including an engaging portion in engagement with one of said first rocking member and said second rocking member and a spherical portion formed at a position thereof above said second rocking member; a detector operable to detect rocking movement in at least one of said first rocking member and said second rocking member to output an electric signal; a cover attached to said case and having a hole defined by an inner peripheral edge that contacts with an outer peripheral surface of said spherical portion, said hole holding said spherical portion so that said lever can be operated in every direction; and a spring provided within said case so as to return said lever to a neutral position by elastically repelling downward said first flat portion and said second portion in a constant manner; said joystick device further comprising a pressing down member disposed between a lower end of said spring and said first and second flat surfaces to have a horizontal surface when said lever is at the neutral position, the repellent force of said spring being transmitted through said press-down member to said first and second flat planes. 